US3621117A - Wrapped insulation-piercing connector - Google Patents

Abstract

This connector consists of a shell, an insulation-piercing type insert, a leaf spring therebetween, and a plastic film bonded to the shell. A spring force on the insert maintains long term contact of the piercing tangs with the conductors. A crimping tool is disclosed having a die with a main-slot wire guide for all splice types. Wires to be severed are led to a branching slot where, during splicing, the shell edge severs conductors therein. Useful for telephone gauge conductors, this connector system requires no insulation stripback or special handling skills.

Description

United States Patent Stanley Casimlr Antas lrvington;

George Thomas Genneken, Whippany; Donald Tolman Smith, Piscataway Township, Middlesex, all of NJ.

Aug. 25, 1970 Nov. 16, 1971 Bell Telephone Laboratories Incorporated Murray Hill, NJ.

lnventors Appl. No. Filed Patented Assignee WRAPPED INSULATION-PIERCING CONNECTOR 9 Claims, 28 Drawing Figs.

us. 01 174/84 c,

29/628, 174/90, 339/97 c. 339/276 R 1111. cr 1102 15/08 Field ofSearch 174/34 c,

90, 94 R; 339/95, 97, 276 R, 276 T; 29/628 [56] References Cited UNITED STATES PATENTS 3,242,256 3/1966 Jugle. 174/84 C 3,303,266 2/1967 Thompson. 174/84 C 3,514,522 5/1970 Kuo 174/90X Primary Examiner- Darrell L. Clay Attorneys-R. J. Guenther and Edwin B. Cave I /V Y PATENTEDNUV 16 ISTI SHEET 2 0F 7 PATENTEBuuv 16 new 3.621.117

saw 6 [1F 7 PATENTEnunv 16 ml SHEET 7 OF 7 FIG. 2/

FIG. 22

FIG. 23

FIG. 26

WRAPPED INSULATION-PIERCING CONNECTOR FIELD OF THE INVENTION This invention relates to the joining of electrical conductors in the 19- to 26-gauge range; and specifically concerns the making of solderless metal-to-metal insulated joints in such conductors.

BACKGROUND OF THE INVENTION Numerous expedients exist for the quick connection of one insulated conductor to another. Among such devices in widespread use are those described in U.S. Pat. Nos. 3,064,072; 3,436,820; and 3,0l2,2l9.

Notwithstanding the general acceptance of the foregoing items, there is yet a need for a splicing system which makes the bridging of conductors easier than at present; and the joining of large-pair-count cable a faster process.

Accordingly, the following are all objects of the present invention:

to simplify conductor insertion in a solderless crimp-type electrical connector;

to obtain better contact performance between the contacting element and the conductor to be joined;

to permit bridging without the cutting of the through conductor;

to achieve a connector design which permits automatic conductor trimming;

to speed up the bridging of conductors in the field; and

to expedite the joining of large-pair-count cable.

SUMMARY OF THE INVENTION These objects and others are achieved by the insulationpiercing connector of the present invention. The connector consists of a shell, a piercing-type insert, a leaf spring therebetween, and a plastic film advantageously bonded to the shell. Connections are effected by a portable tool comprising a die with a main-slot wire guide for all splice types. In the splicing process, the edge of the shell severs conductors which are led up through a branching slot.

The spring force on the insert maintains long term contact of the piercing tangs with the conductors. The insert advantageously is comprised of a spring temper phosphor bronze material which allows the formation of strong tangs. Convolutions at each end of the insert provide mechanical gripping of the conductors to prevent pullout.

The spring is compressed during the crimping, thus applying for the life of the connection a positive compressive force to the insert. A tendency exhibited in many previous designs of tangs to retreat from the conductor, because of a natural tendency for the insert to spring back and because of a long term creep mechanism, is thus avoided.

The shell protects the insert from external disturbance, while transmitting forces between the insert and the spring. A fairly substantial force is generated by the spring in conjunction with an annealed brass shell, which constitutes a preferred inventive embodiment.

The design accommodates a large range of conductor combinations without requiring conductor insulation removal. Thus, connections may be made between two or three conductors ranging in gauge from 19 to 26.

The invention and its further objects, features, and advantages will be readily apprehended from a reading of the description to follow of an illustrative embodiment.

DESCRIPTION OF THE DRAWING prior to crimp- FIG. 4a is a top view of the crimping die jaws of FIG. 4;

FIG. 4b is a frontal perspective view of the die jaws depicted in FIG. 4;

FIGS. 5 through 17 are various side sectional views of the connector of FIG. 2 showing connector bending and crimping sequences occuring in the crimping die;

FIG. 18 is a top perspective view of an alternate embodiment of the body and spring members of FIG. 1;

FIG. 19 is a top perspective view of an alternate embodiment of the spring and insert members of FIG. I; and

FIGS. 20 through 26 are schematic diagrams of various wire connections that may be made by the present invention.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT CONNECTOR CONFIGURATION FIG. 1 shows the components of aconnector 5 in exploded view prior to their being crimped. The shell, designated 10, is an elongated generally J-shaped member made of annealed brass, by a process of stamping. The walls l1, 12 ofshell 10 each include perforations 13, I4 and 15, 16 respectively, symmetrically placed inwardly of the wall ends. On each of the two ends ofthewalls 11, 12 are inwardly extendingtabs 17, 18 and 19, 20 respectively. Thewall 11 is taller thanwall 12, and includes one or more edge extensions such as extensions 2|, 22, 23. To provide a firm cutting edge, the upper edge ofwall 11 is hardened, as by inward compression, creating agroove 24 which extends from the wall end toedge extension 23; and alike groove 25 from the other end ofwall 11 to theedge extension 21.

In the embodiment shown in FIG. I, the spring member designated 30 advantageously comprises an elongated strip made of spring temper phosphor bronze and comprising relativelyflat end portions 31, 32 and a central outwardly protrudingbow portion 33.Spring 30 also includes along its sides.arms 34, 35, which locate in theperforations 13, 14 respectively, ofshell 10; andarms 36, 37 which locate in the perforations l3, 14 respectively, ofshell 10; andarms 36, 37 which locate in the perforations I5, 16 ofshell 10.

The insert designated 40 is likewise made from spring temper phosphor bronze by the process of stamping. Viewed edge-on,insert 40 is .I-shaped and consists of afloor 41, amajor wall 42, and opposite theretominor wall 43.Insert 40 is substantially coextensive in length withshell 10.Wall 42 includescutout portions 44, 45 at its ends, thecutouts 44, 45 engagingtabs 18, 17 respectively ofwall ll ofshell 10, as seen in FIG. 2.

In the embodiment shown in FIG. I, insert 40 consists of afield 46 inwardly protruding tangs centrally located infloor 41; and afield 47 of inwardly protruding tangs centrally located in thewall 42. The tangs of the tang fields 46, 47 are advantageously punched out, with spacings to ensure that any conductor in therange 19 to 26 gauge is contacted. Outwardly of thetang field 46, on either side offloor 41, are formed a series oftransverse ribs 48, 49, 50 at one end and 51, 52, 53 at the other end. Each two adjacent such ribs are provided with spaces between them.Wall 42 ofinsert 40 includes inwardly extendingribs 54,55, 56 at one end and 57, 58, 59 at the other end. The ribs 54-59 likewise are transverse ofwall 42 and advantageously commence at theedge 60 ofwall 42, ending short of thebend line 61 betweenwall 42 andfloor 41. The region between the end of each rib 54-59 and thebend line 61 is provided with raised nipples 62-67, respectively situated opposite the ends of ribs 54-59. The nipples 62-67 prevent wires from escaping from the tangs, and importantly also promote formation of asecond bend line 61a to achieve parallelism between thefloor 41 and thewall 42 after forming, as seen in FIG. 11.

As seen in FIG. 1, the floor ribs 48-50 and the wall ribs 54-56 are staggered in spacing so that when theinsert 40 is folded during the effecting of a connection, these ribs shall interleave. Similarly, the ribs 51-53 are spaced with respect to the ribs 57-59 so that interleaving shall occur when theinsert 40 is folded.

Advantageously, the edge ofmajor wall 42 ofinsert 40 is provided with threecutouts 68, 69, 70; and theminor wall 43 ofinsert 40 is provided withcutouts 71, 72, 73. As seen in FIGS. 10 and 11 during the effecting of a connection and as theinsert 40 is folded, theedge extensions 21, 22, 23 of thewall 11 ofshell 10 are caused to engage the insert cutouts 68-70 and also theinsert cutouts 71, 72, 73. This further locks the insert with respect to the shell.

A plastic film designated 80 is bonded to theshell 10 in the manner shown in FIG. 2, to provide electrical insulation for the metallic parts of the assembly.Plastic film 80 is generally .I-shaped to conform to the shape ofshell 10, but wider thanshell 10, and itswall 82 is longer than thecorresponding wall 12 ofshell 10 as shown in FIG. 2.Plastic film 80 advantageously is corrugated longitudinally to provide both a degree of rigidity and extensibility in the transverse direction. Advantageously, the material from whichfilm 80 is made is a polyester having good mechanical and electric properties as well as environmental stability. The bonding agent is, for example, a polyester adhesive having long term adherence under severe environmental conditions.

An alternate embodiment oftheshell 10 is shown in FIG. 18 in which the spring member is formed directly thereinto. In FIG. 18, certain numerals used in FIG. 1 denote parts which correspond identically to those shown for theshell 10 in FIG. I. This alternate shell of FIG. 18, designatedshell 10a, differs from that shown in FIG. 1 principally in that there is formed directly into thebase 26 ofshell 10a an inwardly extendingbow 33a which corresponds in structure and function to thebow 33 ofspring 30. Theshell 10a combines the structure and functionofshell 10 with thespring 30 shown in FIG. 1.

FIG. 19 shows an alternate embodiment of theinsert 40, designated insert 40a. Here again, certain numerals denote parts of insert 400 which are identical to those designated with like numerals forinsert 40 in FIG. I. The difference between theinserts 40 and 40a is that the central tang fields 46, 47 as well as the ribs 54-59 and 48-53 are replaced by a series of bowed or raised areas which have interleaving transverse serrated edges, these being designatedserrated edges 90 through 97 located inwall 42, and 98 through 105 located infloor 41. The advantage of insert 40a is that a spring such asspring 30 is not necessary as resilience is inherent in this bow shape; and that furthermore, the transverseserrated edges 90 through 97 can be more precisely controlled as to shape and sharpness. The latter permits a more precise control of insulation penetration and contact with the underlying conductor.

Crimping Die FIGS. 4, 4a, and 4b depict a crimping die designated 110 and consisting of a jaw 111 and a die 112. .law 111 is movable in the directions shown byarrow 113. The jaw 111 and die 112 advantageously are mounted on opposing arms of either a handtool or a bench tool (neither shown). Jaw 111 includesarms 114, 115 extending outwardly from, and then parallel to, the interior working surface of the jaw lll, definingslots 116, 117 in which the connector assembly is mounted. The mounting of an assembledconnector 5 is achieved by sliding the corrugated plastic film edges through theslots 116, 117 to achieve a light gripping. The body ofjaw 111 and its working face against which the floor ofconnector 5 seats provides a firm bed with which to force the crimping action.

Die 112 consists of abody 120 mounted between a pair ofside members 121, 122. Each side member includes a mouth defined between thetop surfaces 123, 124 andfront edges 125, 126, respectively. This mouth leads to aslot 127 inside 121 and aslot 128 inside 122.Springs 129, 130 are mounted across theslots 127, 128 and are bowed upwardly to made normal contact with thesurface 123, 124, respectively.Conductor chambers 133, 134 are formed in the region behind thesprings 129, 130 in which, as shown in FIG. 4, theconductors 131, 132 are grippingly accommodated.

Thebody 120 includes anest 140, and a pair of cuttingslots 141, 142. Above thenest 140 is aguide surface 143 with notchedindentations 144, 145, 146 to accommodate theedge extensions 21 22, 23 ofshell in a guiding manner.

Cutting slots I41 and 142 includebevels 147, 148 that serve as a cutting edge for a conductor such as 131 to be bridged. in a manner to be described.

Steps in Forming the Connection The sectional view of FIG. 5 shows conductors I31, 132 suspended across the wire nest and being approached by aconnector assembly 5 which is being forced by the jaw 111.Conductor 131 has been led through thecutting slot 142 preparatory to its severance. The assembledconnector 5 guides into position with itstop wall 11 being guided by thetop surface 149 of thebody 120, and itsbottom wall 12 being guided by thebottom guide surface 150 ofbody 120. It is seen in FIG. 5 that the leadinglip 80a ofplastic film 80 moves in advance of thewall 12. In FIG. 6, thewall 11 leading edge 11a moves against theconductor 131 insulation, driving it against the cutting edge ofbevel 148. FIG. 7 shows the completion of the severance ofconductor 131 in a shearing motion between thebevel 148 and the sharp leading edge 11a. Theconductors 131, 132 are now positioned for envelopment by theconnector 5.

FIGS. 8 through 11 portray the further sequence of crimping taken through a side section that illustrates the guided folding ofedge extensions 21 through 23. In FIG. 8,edge extension 21 is channeled in notchedindentation 146, best seen in FIG. 4b. The leadinglip 80a offilm 80 previously been folded back to the position shown in FIG. 8, by its riding along the curved surface ofnest 140 as seen in FIG. 7. Thus, upon being bent in the notchedindentation 146 as shown in FIG. 8, edge extension 21 (and itscompanions 22 and 23) capture thefilm leading lip 80a, folding it downwardly onto the interior surface ofwall 12.

At about the point depicted in FIG. 8, the leading edge 11a encounters theguide surface 143 depicted in FIG. 4b. Further crimping forms thewall 11 into the bend depicted in FIG. 9 as thewall 11 rides over theextended edge 151 between thenest 140 and theguide face 143. Thebend line 61a is seen in FIG. 8 to be materializing, and furthered in FIG. 9.

By virtue of the bending occasioned in wall 1] by theextended edge 151 and thetop surface 149, thewall 11 assumes the bend depicted in FIG. 10. Here,edge extension 21 by virtue of previous bends is guided intocutout 68ofinsert 40. The leading edge 11a approaches contact with the now completely overlapped leadinglip 80a ofplastic film 80. Theconductors 131, 132 are about to be gripped by the entire series ofribs 48 through 53 and 54 through 59, which are shown in FIG. I. Theleading edge 12a ofwall 12 has been forced into conformity with the curved surface ofnest 140, and is in substantial overlapping relation with the edge Ila. Finally, as depicted in FIG. 11, the crimp is completed.

FIG. 12 is a section taken lengthwise of the wires which shows theribs 48 through 59 gripping the conductors I31 and 132, the latter not shown.

FIGS. 13 through 17 depict the bending sequence taken through a section that includes thetang field 46, 47. The section is taken so as to include anedge extension 21 its notchedindentation forming groove 146. FIG. 14 depicts thetang field 47 as clearing theconductors 131, 132 as the crimping proceeds. Finally, as seen in FIGS. 15, 16, and 17, thewires 131, 132 are enveloped and ultimately their insulation pierced by the tang fields 46, 47. Thespring 30 is finally fully compressed as shown in FIG. 17 to provide lasting contact between the tang fields and the conductors as they are compressed between the spring andwall 11 ofshell 10.

FIGS. 20 through'26 illustrate different types of connections that may be made with the described wrappedinsulation piercing connector 5. In FIG. 20, a bridge conductor is connected to a throughconductor 161. In FIG. 21, twobridge conductors 162, 163 are connected to a throughconductor 164. In FIG. 22, the throughconductor 165 is connected to bridgeconductors 166, 167 both of which exit from one side of theconnector 5.

In FIG. 23 two joinedconductors 168, 169 enter from a single side of theconnector 5; and in FIG. 24,conductors 170 and 171 are connected within theconnector 5. FIG. 25 demonstrates that threeconductors 172, 173, 174 all leading into one side of theconnector 5 may be therein connected. FIG. 26 shows the case of connecting twoconductors 176, 177 coming into one side of the connector to athird conductor 178 leading from the other side.

Numerous other connection schemes are, of course, envisionable, the foregoing being merely illustrative instances.

Various modifications and changes may be made to the inventive embodiment described, and it is understood that all such changes are embraced in the spirit of the invention as defined in the scope of the claims to follow.

What is claimed is: l. A connector for splicing telephone conductors, comprising;

a J-shaped outer shell; a leaf spring loosely mounted on said shell at its base interior; and a metallic insert for receiving and engaging conductors, said insert disposed atop said spring and having a zone of insulation-piercing tangs, the closing of said shell effecting also a full closing of said insert around said conductors and also forming a roof against which said spring compresses said insert. 2. A connector for splicing insulated electrical conductors, comprising:

an elongated outer shell comprising a first wall, a shorter second wall, and a base portion therebetween; spring means disposed on said base portion between said walls and having a springy central region; compliant metal insert means for receiving conductors to be joined, said insert means disposed in said shell atop said spring means and having a major wall, a minor wall and a floor portion therebetween, the major wall and floor portion both having means located in their respective central regions for mechanically piercing said electrical insulation and for engaging the underlying conductor; means on either side of the respective said central regions for securely gripping the insulation of said conductor; means for effecting a joint between said shell first wall and the edge portions of said major wall and said minor wall upon a folding together of said shell and said insert edge portions during crimping; and a plastic film enveloping said shell exterior. 3. A connector in accordance with claim 2, further comprising means for mounting said spring means on said base comprising at least one extension on each edge of said spring and a like number of cavities in each said shell first and second walls for engaging of said extensions.

4. A connector in accordance with claim 2, wherein said mechanical piercing means comprises opposing tang fields in the central regions of said major wall and said floor portions. and wherein said gripping means comprises plural protruding ribs spaced transversely on either side of each said tang field, said ribs being staggered to interleave with one another upon folding of said major wall over said floor portion during crimpmg.

5. A connector in accordance with claim 4, wherein the boundary between said major wall and said floor portion of said insert constitutes a first bend line and said insert further having a plurality of protruding nipples located beyond the interior end of each rib on said major wall, the region between said plural nipples and said major wall plural ribs constituting a zone for effecting a second bend line during folding of said insert means.

6. A connector in accordance withclaim 5, further comprising means for mounting said insert on said base, comprising an upwardly extending tab at each end of said first wall and of said second wall of said shell, for engaging the four corners of said insert means.

7. A connector in accordance with claim 6, wherein said plastic film overlaps said shell at the ends thereof, said film further having plural longitudinal corru ations, said film being affixed to san shell exterior, one film e ge extending substantially beyond the edge of said shell second wall for overlapping of same on completion of said folding.

8. A connector in accordance with claim 2, wherein said joint-effecting means comprises at least one edge extension of said shell first wall, and corresponding notches in the edges of said insert major and minor walls respectively, for engaging said first wall extensions.

9. A connector for splicing insulated electrical conductors, comprising:

a J-shaped outer shell having a resilient bow-shaped base;

a metallic insert for receiving and engaging conductors, said insert disposed within said shell and having insulationpiercing tangs, the closing of said shell effecting also a full closing of said insert around said conductors and also forming a roof against which said insert is compressed.

Claims (9)

1. A connector for splicing telephone conductors, comprising; a J-shaped outer shell; a leaf spring loosely mounted on said shell at its base interior; and a metallic insert for receiving and engaging conductors, said insert disposed atop said spring and having a zone of insulation-piercing tangs, the closing of said shell effecting also a full closing of said insert around said conductors and also forming a roof against which said spring compresses said insert.

2. A connector for splicing insulated electrical conductors, comprising: an elongated outer shell comprising a first wall, a shorter second wall, and a base portion therebetween; spring means disposed on said base portion between said walls and having a springy central region; compliant metal insert means for receiving conductors to be joined, said insert means disposed in said shell atop said spring means and having a major wall, a minor wall and a floor portion therebetween, the major wall and floor portion both having means located in their respective central regions for mechanically piercing said electrical insulation and for engaging the underlying conductor; means on either side of the respective said central regions for securely gripping the insulation of said conductor; means for effecting a joint between said shell first wall and the edge portions of said major wall and said minor wall upon a folding together of said shell and said insert edge portions during crimping; and a plastic film plastic film enveloping said shell exterior.

3. A connector in accordance with claim 2, further comprising means for mounting said spring means on said base comprising at least one extension on each edge of said spring and a like number of cavities in each said shell first and second walls for engaging of said extensions.

4. A connector in accordance with claim 2, wherein said mechanical piercing means comprises opposing tang fields in the central regions of said major wall and said floor portions, and wherein said gripping means comprises plural protruding ribs spaced transversely on either side of each said tang field, said ribs being staggered to interleave with one another upon folding of said major wall over said floor portion during crimping.

5. A connector in accordance with claim 4, wherein the boundary between said major wall and said floor portion of said insert constitutes a first bend line and said insert further having a plurality of protruding nipples located beyond the interior end of each rib on said major wall, the region between said plural nipples and said major wall plural ribs constituting a zone for effecting a second bend line during folding of said insert means.

6. A connector in accordance with claim 5, further comprising means for mounting said insert on said base, comprising an upwardly extending tab at each end of said first wall and of said second wall of said shell, for engaging the four corners of said insert means.

7. A connector in accordance with claim 6, wherein said plastic film overlaps said shell at the ends thereof, said film further having plural longitudinal corrugations, said film being affixed to said shell exterior, one film edge extending substantially beyond the edge of said shell second wall for overlapping of same on completion of said folding.

8. A connector in accordance with claim 2, wherein said joint-effecting means comprises at least one edge extension of said shell first wall, and corresponding notches in the edges of said insert major and minor walls respectively, for engaging said first wall extensions.

9. A connector for splicing insulated electrical conductors, comprising: a J-shaped outer shell having a resilient bow-shaped base; a metallic insert for receiving and engaging conductors, said insert disposed within said shell and having insulation-piercing tangs, the closing of said shell effecting also a full closing of said insert around said conductors and also forming a roof against which said insert is compressed.

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